The 180,000 km² of Arabian lava fields (“harrats” in Arabic) form one of the largest distributed basaltic provinces in the world. Approximately 50% of these are located in Saudi Arabia. The most recent eruption in 1256 AD, as well as seismicity and ground deformation associated with shallow dike emplacement in...
The Cook-Austral island chain has been the center of debate for many years. Contrary to the classical hotspot hypothesis, this volcanic island chain does not exhibit a linear age progression with a single node of active volcanism, but instead shows evidence of young volcanism at several points along the chain....
The eruptive history of the Quaternary Cascades arc has been relatively well characterized. However, much less is known about the frequency and sizes of explosive eruptions produced by earlier stages of the arc. The Late Neogene Deschutes Formation of Central Oregon preserves a remarkable record of heightened pyroclastic activity during...
The spatial distribution and geologic histories of submarine volcanoes provide insight into submarine eruptive behavior, deep earth processes and plate tectonics. This dissertation examines the evolution of individual submarine volcanic edifices as well as linear trails of seamounts at three spatial and temporal scales.
In order to understand constructive and...
Earth’s mantle extends to nearly 3000 km depth, comprises >80 % of Earth’s total volume, and has the largest influence on the primordial and radiogenic heat budget. Despite its importance, the structure and composition of the mantle is still debated. There are three primary models for Earth’s mantle structure that...
Inheritance from pre-existing mantle domains and fluid and melt contributions from active subduction together produce the geochemical signatures of mantle-derived arc basalts. In this context, this work evaluates the evolution of Cascadia mantle sources by documenting the isotopic and compositional characteristics of primitive basalts along a transect across the Eocene-Oligocene...